The invention relates to a millwork for a grain mill, provided with a driven lower mill stone and a fixed upper mill stone. The lower mill stone is positioned rotatably on the lower section of a millwork. The upper millstone has a central inflow opening for the mill product, and is installed in an upper mill stone support. The upper mill stone is positioned such that it can be adjusted in height (axially) but cannot be turned, whereby the upper and lower mill stones are adjustable axially relative to one another for the adjustment of the grinding gap formed between the mill stones.
Grain mills of that type serve to grind small quantities of grain mainly for immediate use. They are installed in households, but also in stores or in restaurant kitchens or for institutional use. It is important for achieving good grinding quality to assure an exact adjustment of the grinding gap. The grinding gap is to remain unchanged when in operation; an adjustment of the grinding gap is required to change the result of the grinding in a desired way.
In a known grain mill (WO 91/18545) the upper mill stone is positioned elastically, although unadjustably in the mill housing. The adjustment of the grinding gap results from an axial adjustment of the motor groove carrying the lower mill stone. For this, the use of a motor with an axially adjustable motor shaft is required.
The elastic mounting of the upper mill stone, so mounted for the purpose of damping the noise, hampers the precise axial adjustment of the grinding gap. A disassembly of the millwork, for instance for cleaning purposes, is so costly that it cannot be conducted readily by the user himself. For a known grain mill with a millwork of the type noted above (DE 35 35 119 A1, FIG. 2) the support for the upper mill stone is designed as a casing arranged axially adjustably on the mill housing. An adjustment mechanism required for the adjustment of the grinding gap and a possible means to open the millwork for cleaning purposes are not described.
In German Patent Application P 43 26 926.5, the upper mill stone support is arranged axially adjustably between the lower section of the millwork and a cover rigidly connected to the latter. The adjustment mechanism for the upper mill stone support is placed in the cover and comprises two adjustment rings in contact with a screw surface, wherein one ring is attached so that it cannot turn and the other ring is rotatably positioned and provided with an adjustment handle projecting outward. The space requirement for the adjustment mechanism is relatively large. To open the millwork, the cover with the adjustment mechanism and the upper mill stone support must be removed.
The task of the present invention is to design a millwork so that the adjustment mechanism necessary for the adjustment of the upper mill stone support requires little space and is simple to mount, and thus makes possible an adjustment of the grinding gap that is unchangeable during operation.